Multiple yarn feed circular hosiery knitting machines



June 13, 1961 MAHLER 2,987,899

MULTIPLE YARN FEED CIRCULAR HOSIERY KNITTING MACHINES Filed May 5, 1959 4 Sheets-Sheet 1 P. A. MAHLER June 13, 1961 MULTIPLE YARN FEED CIRCULAR HOSIERY KNITTING MACHINES Filed May 5, 1959 4 Sheets-Sheet 2 ,R K MV 7,,

Hg. 6, 931. my U s P. A. MAHLER June 13, 1961 MULTIPLE YARN FEED CIRCULAR HOSIERY KNITTING MACHINES Filed May 5, 1959 4 Sheets-Sheet 3 June 1961 P. A. MAHLER 2,987,899

MULTIPLE YARN FEED CIRCULAR HOSIERY KNITTING MACHINES Filed May 5, 1959 4 Sheets-Sheet 4 L 54B 4 005 r i if; b

This invention relates to improvements in circular hosiery knitting machines of the dual feed type.

In machines of this type, it is necessary by reason of machine limitations to produce the heel pocket of the stocking, wherein the needle cylinder is oscillated, by single feed operation. The dual feed operation, used in producing the tubular leg of the stocking by circular knitting is accordingly discontinued at the beginning of the heel, and is continued again after completion of the heel pocket for subsequent formation by circular knitting of the tubular foot of the stocking.

The changeover from dual feed to single feed involves the withdrawal of one of the dual yarns from the needles in one course of knitting and the termination of that course in a loose end of yarn. While conventionally this yarn is knitted into the fabric up to the point of retraction in normal manner, the fact that the loose end is not positively anchored, creates a tendency for the loop or loops immediately adjoining the said point of retraction to expand and loosen under strain imposed on the fabric and consequent formation of a gap or hole in the fabric. It is an object of this invention to overcome this fault.

When, in dual feed knitting, one of the yarns is withdrawn and severed, thereby terminating one course, the preceding and following courses, both produced by the remaining yarn, will merge to continue the fabric from the single feed. The said merger occurs immediately after the terminal loop in the interrupted course and at the point of yarn withdrawal. The severance of this yarn does not occur immediately after withdrawal but at some distance from the terminal loop thereby leaving a trailing end of considerable length, which, conventionally is cut away by hand at a point near the loop. The present invention contemplates the use of this extended and unsevered end as a medium for anchoring the loose end of yarn in the fabric so as to preclude formation of the undesirable gap or hole described above.

To this end, it is proposed to guide the yarn and manipulate the needles so that the end, or at least that part of it which immediately adjoins the terminal loop in the interrupted course, shall be picked up by the needles and knitted into the fabric with and in the same manner as the yarn from the continuing feed source which forms the following course. The length of loose end so knitted in will be adequate to form a positive anchor for the interrupted course of loops and to preserve those loops substantially intact and unmodified by the strains to which the stocking may normally be subjected.

It will be apparent that conventionally the same faulty condition will prevail when the dual feed knitting operation is re-established at the completion of the heel pocket. Reintroduction of the second yarn again entails the formation of an extended loose end which normally is cut away manually from a point in proximity to the initial loop of the new course initiated by the second yarn. In this case also it is proposed to manipulate the needles and the loose end so that the latter or a portion thereof immediately adjoining the said initial loop shall be knitted into the fabric by inclusion with the loops of the course in process of formation at the movement the, second yarn is inserted.

It is evident that the knitting in of the loose ends as ted States Patent C F described above will in effect double the yarn in the courses and areas affected and would tend to thicken the fabric and give it a flawed appearance. The invention contemplates a substantially complete concealment of the marks by bringing the loops containing the loose ends into substantial coincidence with the gore lines which are a necessary concomitant to the formation of the heel pocket, as well understood in the art, and which appear at opposite sides of the heel of the conventional circular knit stocking.

The invention will be more readily understood by reference to the attached drawings, wherein:

FIG. 1 is a side view of a stocking made in accordance with the invention;

FIG. 2 is an enlarged fragmentary face view of the left side of the stocking;

FIG. 3 is a like view of the right hand side;

FIG. 4 is a development of the heel pocket of the stocking;

FIG. 5 is a greatly magnified view of the area of the stocking fabric embraced by the rectangle appearing in broken lines in FIG. 2;

FIG. 6 is a like view of the area embraced by the broken lines in FIG. 3;

FIG. 7 is a development in part of the cam ring of a knitting machine of the character to which the invention relates showing the needle and jack cams immediately involved in the present invention with the represpective needle paths indicated in broken lines;

FIG. 8 is a fragmentary view in perspective showing the dial plate, the elements of the yarn feed, a part of the needle series;

FIG. 9 is a similar view showing the elements of the yarn feed in different positions of adjustment;

FIG. 10 is a fragmentary View in perspective showing the details of the yarn clamping and severing elements of the feed mechanism;

FIG. 11 is a fragmentary view illustrating the function of the sinkers to control latch clearance of a yarn loop carried by one of the needles;

FIG. 12 is a similar fragmentary view illustrating a detail of structure and operation;

FIG. 13 is a fragmentary vertical sectional view showing the relation of the needles to yarn in different positions of the yarn feed fingers;

FIG. 14 is a schematic view showing one of the yarn feed fingers and the immediate section of the needle cylinder at the time of yarn introduction;

FIG. 15 is a like view showing the needles and finger during the period of yarn withdrawal;

FIG. 16 is a schematic 'view of the needle circle;

FIG. 17 is a development of the cam ring of another embodiment of a knitting machine made in accordance with the invention showing the needle and jack cams employed in the present invention and showing the needle paths during withdrawal of the auxiliary feed;

FIG. 18 is a development similar to FIG. 17 showing the needle paths during reinstatement of the auxiliary feeds;

FIG. 19 is an illustration of the needle butts embodied in the latter embodiment of the invention; and

FIGS. 20 and 2.1 are fragmentary axial sectional views showing the auxiliary clearing cam of the latter embodiment of the invention and the relative positions of the various needles relative to the sinkers as they pass the cam.

With reference to FIGS. 1 to 6 inclusive of the drawings, the heel pocket of the stocking 1 is indicated by the reference numeral 2, and 3 indicates collectively the gore marks which appear at the opposite sides of the heel and which are an unavoidable result of the machine process used in the knitting of this portion of the stocking. As previously described, the dual yarn feed is tQl'e minated with the initiation of the oscillatory operation at the heel and the point of termination relative to the gore marks is best illustrated in FIG. 5. The feed from one of the yarn feed stations, hereinafter identified as station B, is interrupted at the point 5 in course 6 and the terminal loop of this course may be identified also by the number 5. In accordance with the invention, the loose end 7 extending from the loop 5 is knit with the yarn 8 of the course 9', which immediately follows the course 6, through the loops of the next preceding course 11. Course 9 is formed from yarn fed from the other of the yarn feed stations which will be identified hereinafter as station A; and the subsequent courses making up the heel pocket will be composed of yarn drawn solely from station A. The yarn for course 11, lying in the dual feed area of the leg, will be drawn from station A. In course 9, the loops which immediately follow the position of the terminal loop 5 are-the composite loops 10' which contain in addition to the normal loops of the course, the loops formed from the loose end 7 as described above.

The course 9, which merges as described with course 6, may be considered the last course of circular knitting prior to institution of the oscillatory action which forms the heel pocket. The first oscillation begins at the point 12 in FIG. 6 and the initial pass of that oscillation terminates at the point 13 in FIG. 5. From these points, as best shown in the development of FIG. 4, the oscillations are progressively narrowed by withdrawal of needles to the points 14 and 15; then widened by reverse process to the points 16 and 17; again narrowed to the points is and 19; then widened in a single course from the points 18 and 19; to the initial points 12 and 13; further widened by progressive needle insertion from the points. 12 and 13 to the points 21 and 22, and finally again narrowed progressively to the points 23 and 24 where the full circular knitting and dual yarn feed are restored.

It will be noted that the gore line which extends between the points 13 and 22 is formed by the interlacing of the terminal loops of progressively widened courses of oscillatory knitting described above, with the loops of the last preceding course of full circular knitting. In other words, the said terminal loops interlace with the three loops of course 9 which are knit with the three loops of course 6 which terminate that course, and also interlaced with the following loops of course 9 including the composite loops 10. Thus, the composite loops substantially coincide with and in effect are incorporated in the gore mark to an extent rendering them substantially invisible to the naked eye. Not only is the loose end 7 securely anchored in the fabric to the material advantage described above, but the otherwise adverse effect of the anchored end on the appearance of the stocking is avoided.

The same method is employed for anchoring the loose end of yarn which attaches to the initial loop of the second feed yarn when re-introduced at station B, and for rendering the anchored end invisible. In this case, however, as shown in FIGS. 3, 4, and 6, the composite loops 25 of which the said yarn end forms a part, see FIG. 6, coincide with the gore mark extending between the points 21 and 23, this line paralleling the adjoining parts of the initial course 26 of full circular knitting at restoration of the latter at completion of the heel pocket. The positions of the composite loops and their relation to the loops of the adjoining courses and to the gore mark are clearly shown in FIG. 6 and indicated in FIG. 3.

One mechanical means for achieving the aforedescribed results is illustrated in FIGS. 7 to 16 of the drawings. The yarn feed stations A and B are shown in FIG. 7 and also the needle cams associated with said stations. Sizemarking cams 27 and 28, as described in my US. Patent No. 2,827,780, are withdrawn out of the path of the needle butts during the operation of this means. At station A, the cams comprise the conventional latch clearing and stitch cams 31 and 32 which function for both directions of needle travel in the. usual manner. At station B, the cams include a latch clearing cam 33 and a stitch cam 34 both of which are adjustable radially of the needle cylinder as and for purposes hereinafter described. The cams 33 comprise lower and upper radially off-set portions 35 and 36 respectively. The essential mechanism comprises also needle jacks, of which one is indicated at 37, and adjustable jack earns 38.

The needle circle comprises needles of three differing butt lengths arranged. in groups as indicated in FIG. 16. The continuous series B extending clockwise from point 39 to point 41 has butts of major length. Between the points 41 and 42, the needles, numbering six in the present instance, are of intermediate length and this series of intermediate butt needles will be hereinafter identified as group C. From the point 42 to point 43, in the series F, the butts are of minor length; and in the series of six needles 43 to '39, five of the needles have buttsof the said intermediate length and the remaining needle, which occupies an intermediate position in the series, is of the said minor butt length. This entire series of six needles will be hereinafter referred to as group D.

As previously stated, the feed of yarn from station A may for the purpose of this invention, be considered constant. Change from dual to single feed operation and the reverse are functions of the feed at station B. In interrupting the feed at this station, the yarn feed finger 44 is elevated so as to withdraw its yarn 45, see FIG. 9, from the needles in conventional manner. In accordance with the invention, this occurs at the leading end of group C of the intermediate butt needles so that normally the yarn would leave the needles between the first needle of the said group and the last or trailing needle of the major butt series B, all with reference to direction of cylinder rotation as indicated in the drawings. Prior to the movement of the needles of group C into station B, however, the earns 33 and 34 are retracted to an. extent such that, while not affecting the normal elevation of the preceding major butt needles to latch clearing position and subsequent depression thereof to cast their loops, the intermediate length butts of the group C needles will not engage the upper part 36 of cam 33 and also cam 34. The lower part 35 of cam 33, still active on the intermediate length butts, will lift the needles of the group to a semi-elevated position, as shown in FIG. 11 for example, wherein the yarn loops then carried by the needles will clear the latch, and since the cam 34 is also retracted to an inoperative position with respect to the needles, the latter remain in the semielevated position and follow the path 71, as indicated in the diagram of FIG. 15. This figure shows also that the major butt needles, preceding the group C needles past the feed station and elevated to the latch clearing position by cam 33, were subsequently depressed by cam 34 to cast their loops in normal fashion as indicated at 72. This particular course of knitting will terminate with the loop formed by the last or trailing needle of the major butt length series, and in FIG. 5, this loop, formed from yarn picked up at station B, has been identified by the reference numeral 5. As shown also in the diagram of FIG. 15, the needles of the minor butt series following the group C have been unaffected by retracted cam 33, and these needles will also miss cam 34 and will therefore retain their loops and will track in the path at the same elevation, as indicated at 73, and will merge with the major butt needles beyond the cam 34.

As previously stated, the elevation of the finger 44 was timed so that normally the yarn 45 would leave the needles between the leading needle of group C and the trailing needle of the major butt series. By reason of the elevated position of the C group needles, however, as shown in FIG. 15, the yarn does not clear these needles and will lie 'at the outer sides thereof. As the needles advance and, as shown in FIG. 9, the trailing end of the yarn is carried by the needles under the resilient yarn anchoring finger 46- on the dial 47, and over the lower blade 48 of a shear of which the upper movable blade, now in elevated position, is shown at 49. Except in the details hereinafter described, the finger 46 and shear 48, 49 may be considered conventional. At the position shown in FIG. 9, the blade 49 is tripped to move downwardly and thereby sever the yarn 45. In this position also the needles are moving into yarn feed station A.

It will be noted, as shown in FIG. 9, that between the station B and the position of the yarn cut-01f, the needles of the major butt series and also those of the minor butt series, have been elevated to latch clearing height. This elevation, which occurs at position X in FIG. 9, is eifected by jacks 37, see FIG. 7, and jack cams 38 which may be inserted at the proper point into the paths of the jack butts, it being noted however that by reason of the special form of the jacks of the C group needles, the position of the needles of the group C are not affected by the cams 38 so that these needles remain in the semielevated positions previously described and as indicated in FIG. 9. As also illustrated in FIG. 9, and also in FIG. 11, the trailing end of the yarn from the terminal loop 5 has been supported on the sinkers 52 above the lower ends of the needle latches 53. It will be noted also that following elevation of the needles at X, the trailing yarn end will pass inwardly of the needle circle between the trailing needle of group C and the leading needle of the minor butt series.

At this point, therefore, the needles of group C carry loops of yarn previously picked up at station A and in position for casting. They also have the trailing end of yarn from station B lying across their faces but above the latch ends. When these needles move into yarn feed stations A, the cam 31 of that station will have been retracted so as not to engage the group C needles so that the latter will not be elevated and the said trailing end of yarn from the terminal loop 5 will lie above the latch, and will be drawn downwardly by cam 32 to carry that yarn, together with the new yarn picked up at station A, through the cast loop to form the composite loops 7, 8 previously described. The other needles passing into station A were previously elevated by the cams 38 and their loops are in the latch clearing position, so that they cast their loops at that station independently of cam 31. In this manner, the loose end of yarn from terminal loop 5 is knit by the group C needles into the fabric as clearly illustrated in Fig. 5.

The same device is utilized to anchor the loose end of yarn formed when the yarn feed is restored at station B. The sequence of operations is illustrated in FIGS. 6, 8, l2 and 1'4. In this case, the finger 44 is depressed to insert the yarn '45 between the leading needle of the group D and the trailing needle of the minor butt series. The latter needle is indicated in the drawings by the reference numeral 54. At the point of introduction, the group D needles carry loops received at station A, but these loops are not cast at static-n B as hereinafter described. The preceding minor butt needles in the group F also carry loops picked up at station A but these needles receive no yarn in passing through station B and were not elevated to latch clearing position at that station by reason of retraction of the cam 33, following the path 73. The lower part of cam 33 is engaged by the intermediate length butts of the group D needles and therefore elevates those needles in the path 71 to the same elevated positions wherein the loops carried from station A are cleared of the latches and the yarn 45 is intercepted by the leading needle of the roup as shown in full lines in FIG. 8. It will be noted, however, that in group D, the one needle 55 of minor butt length, previously referred to, was not raised by cam 31 and therefore leaves the station in the same depressed position in which it enters, as have the other needles of corresponding butt length in the path 73. It should be noted also that the intercepted yarn lies against and above the lower ends of the latches of the group D needles and is supported in this position by the sinkers 52 as previously described. The upper end of the needle 55 therefore lies below the level of the yarn :as indicated in FIG. 14.

. As the needles progress, means is provided to intercept the yarn section extending within the cylinder for drawing the yarn tautly across the needles of group D. To this end, the yarn 45 from finger 44, having its loose end clamped on the dial plate by the finger 46, is looped by the needle progression about a pin 56 on the said plate, as shown in FIG. 8, so that the yarn is held tautly across the fronts of the group D needles. In the meantime, the leading needle 57 of the major butt series B following group D, has been actuated at station B to take the yarn 45 and to cast the loop previously picked up at station A, and the new loop of yarn 45 constitutes the initial loop of the now restored dual feed. In FIG. 6, this loop has been indicated by the numeral 57.

As the loop of yarn formed about the pin 56 progresses to the position indicated in broken lines in FIG. 8, the yarn end extending from the leading needle of group D passes under the finger 46, but the finger at this point, and as hereinafter explained, exerts small clamping pressure on the yarn so that the end is pulled away from the finger without excessive tension and possible yarn rupture at an intermediate point.

As the needles move into the dotted line position at X in FIG. 8, they are elevated by the cams 38 and associated jacks, with the exceptions set forth below, to latch clearing position. The exceptions are those needles of the group D which already occupy the aforesaid semi-elevated position. The needle 55, however, is elevated, but by reason of the fact that the yarn end 45 lies above the upper end of this needle and tautly against the latches of the other needles of the group, the needle 55 passes in front of the yarn in the manner illustrated in FIG. 12. The needle is thereby operative after severance of the yarn to retain the yarn end securely against the other needles of the group so that When, at station A, the needles after picking up the new yarn are depressed to cast their loops, the yarn end will be carried down with the said new yarn to form the composite loops indicated at 25 in FIG. 6. The needle 55 in its downward movement, will miss the yarn end and the yarn will float between the immediately adjoining wales as indicated at 59. The loose end thus knitted into the fabric is securely anchored as described above. As the yarn section between the pin 56 and the cylinder passes under the shear blade 49, the latter is actuated to sever the yarn.

It will be noted that in this case also, the tying in of the loose end' of yarn as described above, occurs in immediate proximity to the gore markings on the right side of the heel of the stocking, specifically the mark lying between the point 21, see FIG. 4, and the terminal point 23 of oscillatory knitting. The double thickness of yarn in the loops 25 is thereby concealed and substantially invisible to the naked eye.

49. The lower shear blade 48 is fixed and the upper blade "oscillates about a pivot bolt 61 in a block 62 secured to the dial plate 47. The finger 46 is also fixed at its rear end to the dial plate. Also pivotally mounted on the bolt 61 is a lever 63 which carries a block 64 at its forward end and has also a pin 65 which projects through a slot 66 in blade 49. The slot and pin constitute a lost-motion means aifording limited free motion between the blade and the lever. The spring 51 attached to the lever 63 tends to move the forward end downwardly to a position in which the block 64 will bear against. the top of the finger 46 to augment its yar-n clamping capacity, but this movement of the lever is permitted only when the blade 49 moves downwardly in its working stroke or occupies the closed position with respect to the fixed blade 48. However, by such arrangement, adjustment of the tension of spring 51 may be utilized to vary the degree of pressure applied to the clamping finger by block 64' independentbf the means normally applied to operate the-shear blade 49 to closed position. By this means, the clamping pressure of the block on the finger during the withdrawal of the yarn end in the operation illustrated in FIG. 8 and described above may be regulated to avoid yarn rupture.

Another mechanical means for achieving the results desired is illustrated in FIGS. 17-21. In this embodiment of the invention, the yarn feed stations A and B are provided with needle cams which are substantially identical to the cams at the stations A and B of the previously described embodiment. These cams have been given identical reference numerals. Instead of employing special jacks to selectively elevate all of the needles except the needles of groups C and D, an auxiliary clearing cam 81 is mounted for adjustment into and out of the path of the needle butts traveling from station B to station A. The clearing cam 81 may also serve the function of the size marking cams 27 and 28 of the previously described embodiment, as will be apparent by reference to the aforementioned Patent No. 2,827,780. The jack cams 38 operate on the conventional jacks 37 to elevate those needles which are not engaged by the clearing cam, as more fully described hereinafter.

The needle circle comprises needles of differing butt lengths arranged in the same groups as indicated in FIG. 16. The continuous series E has butts of major length, for example as indicated at 82 in FIG. 19. This major length will vary throughout the series to perform the usual functions of the knitting machine. The needles in the group C following the group E have butts of intermedi ate lengths and are provided with a cut-out or notch as indicated at 83 in FIG. 19. The needles in the series F following the group C have butts of minor length for example as indicated at 84, selected minor butt needles being extra short for stitch marking, and the needles of the group D are identical to those of group D of the previously described embodiment comprising butts of intermediate lengths as indicated at 85 in FIG. 19 on five of the needles and a minor butt length on the sixth needle in an intermediate position within the series.

The operation of the knitting machine is similar to that described in connection with the previous embodiment. To this end, prior to withdrawing the yarn by raising the feed finger 44 at a position between groups B and C, the cam 33 is retracted so that the upper level 36 engages only the major butt needles 82 (group B) and the lower part 35 engages in the notch 83 of the needles of the group C. The minor butt length needles 84 (group F) do not engage the cam. The cam 34 is also retracted so as to engage only the major butt length needles 82 permitting the needles of groups C and F to pass without being depressed. Thus, the needles 82 (group B) follow the path 86 shown in FIG. 17, the needles of group C follow the path 87 and the needles of group F follow the path 88. It is noted that the path 87 is slightly lower than the path 71 shown in FIG. 7 by reason of the engagement of the notch 83 with the lower portion 35 of the cam. The paths difference in this position corresponds to the vertical depth of the notch 83, which may be in the order of 0.030 inch. In the path 86, the major butt length needles (group E) are drawn to cast their loops and are returned to the tuck level coincident with the needles (group F) in the path '88.

Concurrently, with the actuation of the cam 33, the clearing cam 31 is retracted and the auxiliary cam 81 is positioned in an intermediate position so as not to engage the short butt needles 84 while engaging in the notch 83 of the needles of group C and engaging the bottom of the butts 82 of the needles of group E. Since it is desired to elevate all of the needles except those of group C to the latch-clearing position prior to knitting at station A, the jack cams 38 are operated to cooperate with the jacks 37 of the needles of group F to elevate the same. It is noted that the needles of group F are 8 provided with long butt jac'kswhereas the remaining needles are provided with shorter butt jacks.

Thus, the actuation of the cams causes the needles of group F to be elevated to the path 89 at the station X. The major butt length needles of the group B engage the clearing cam 81 and are displaced to the path 90, at which level the latch'clears the loops formed at the feed station E. It is noted that the upper surface of the cam 81 is at a common level with the lower portion of the cam 35 so that the needles of the group C track at the same elevation 87 past the cam 81 inasmuch as the cam passes into the notch 83.

At the feed station A, the clearing cam 31 has been retraoted so that the needles of groups E, C, and F enter the feed station A at their respective elevations at 90, 87, and 89 to take the yarn, and the yarn is formed into needle loops by the stitch cam 32 which operates on all of the needles. The notch 83 in the needles of group C insures that the lower end of the latch of the needles is between the levels of the upper surface of thesinker and the throat thereof, and that the yarn bearing on the upper surface of the sinkers is positively positioned above the lower end of the latch, and composite loops are formed on the needles of this group. Following the passage of the needles of group C past the clearing cam 31, this cam is reinstated into action and the clearing cam 81 and jack cams 38 are reinstated to their original position.

When putting the auxiliary feed back into action, the same sequence is followed. As shown in Fig. 18, the major butt needles 82 (group E) follow the paths 86 and 90 under the influence of cams 36, 34, and 81, the minor butt length needles 84 (group F) follow the paths 88 and 89 under the influence of the jack slides 38, but the needles of group D having an intermediate butt length without a notch, follow a path 92 which corresponds to the path 71 shown in Fig. 7 under the infiuence of the cam part 35. The minor butt length needle in group D follows the paths 88 and 89. The needles 85 of group D need not be notched since the free yarn end resting on the sinkers is not drawn tautly against the upper surface of the sinkers as is the case where the yarn is being withdrawn from action. This results from the fact that whereas the withdrawn yarn end is held in the throat of the sinker adjacent the final needle of group E, the newly inserted yarn rests lightly on the tops of the sinkers, and is free to be drawn upwardly on the latch by the tensioning. means between the needle circle and the axis of the cylinder.

Thus, the present embodiment of the invention provides means for positioning the intermediate butt length needles of groups C and D at a semi-elevated position, the semi-elevated position for group C being slightly lower than the semi-elevated position for group D. Also, in this embodiment of the invention, the long butt needles of group E enter the feed station A at the higher semielevated position and are not elevated to the full clearing position normally efiected by the cam 31. The semielevated position in each case is sufficient to clear the latch of the loops in the throats of the sinkers. The relationships of the needles to the sinkers is shown clearly in Figs. 20 and 21.

This application is a continuation-in-part of my copending application, Serial No. 616,002, filed October 15, 1956, now abandoned.

While particular embodiments of the present invention have been herein illustrated and described, it is not intended to limit the invention to such disclosure, but changes and modifications may be made therein and thereto within the scope of the following claims:

I claim:

1. In a circular knitting machine having two yarn feed stations relatively spaced circumferentially of the needle cylinder, said cylinder carrying sinkers and two series of needles having butts of minor and major lengths, respectively, and two relatively small series of intermediate butt length separating the ends of the two series first named, latch clearing and stitch cams at'each feed station cooperable with the sinkers to form needle loops, the clearing cam at the first of said stations having upper and lower sections relatively ofiset radially of the cylinder. with the said upper section relatively remote to the cylinder axis, the latter cam being adjustable radially between alternative positions in one of which both the said sections are operative with respect to the butts of all the needles to raise the needles to latch clearing elevation, and in another of which the lower section only is operative on the needles of the intermediate series to raise those needles to a semi-elevated position, the cam in the latter position being inoperative with respect to the minor butt needles, said sinkers being cooperative with the semielevated needles to support yarn fed to the latter against the latches to prevent clearing the latter, and the formation of needle loops, the clearing cam at the other station being adjustable between operative and inoperative positions with respect to all the said needles, jacks for said needles, and cam means at a position between said stations and following the first of said stations with respect to direction of cylinder rotation and operative to elevate only the needles of major and minor butt lengths to clear the needle loops from the latches thereof.

2. A machine according to claim 1 wherein said cam means comprises jack cams operable only upon the jacks of said major and minor butt-length needles.

3. A machine according to claim 1 wherein said cam means comprises jack cams operable only upon the jacks of said minor butt-length needles and an auxiliary clearing cam in the path of said major butt length needles to engage the latter and elevate the same to clear the needle loops, said clearing cam being operable to not engage said intermediate butt length needles.

4. A machine according to claim 3 wherein said auxiliary cam has a height corresponding to the height of said lower offset section of the clearing cam for the first station.

5. A machine according to claim 1 wherein one of said small series of intermediate butt-length needles is provided with a notch at the lowermost outer corner of the butt, said notch being operable to engage over the offset lower section of the clearing cam for the first station.

6. In a circular knitting machine having a rotary needle cylinder and two yarn feed stations relatively spaced circumferentially of the cylinder, latch needles of differing butt lengths in said cylinder, needle-actuating cam means at each said station, yarn feed means at each station for inserting and withdrawing yarn in and from the needles, said feed means operating in timed relation with the rotary movement of the cylinder to withdraw the yarn at a predetermined point of the cylinder circumference, said cam means cooperable with the yarn feed means to elevate a selected group of needles at one of said stations immediately following the point of yarn withdrawal and to retain the needles in said elevated position to intercept the withdrawn end of yarn, means for retaining the yarn end against the needle latches including yarn-engaging means exterior of said cylinder to position the yarn end above the latch clearing position as the latter needles move toward the second of said stations, and cam means for elevating the needles other than those of the said selected group to latch clearing position prior to the movement into the said second station, the cam means and yarn feed at said second station being actuatable to cause all the needles to take yarn and to cast their respective loops.

7. In a circular knitting machine having a rotary needle cylinder and two yarn feed stations relatively spaced circumferentially of said cylinder, latch needles in said cylinder having butts of differing lengths, yarn feed means at said stations including devices for inserting and withdrawing yarn in and from the needles, cam means at said stations for actuating the needles to form the knitted 1O loops, said devices being act atable in timed relation with the rotary movement of the cylinder to insert a yarn at a predetermined point on the cylinder circumference, said cam means at one of.said stations being actuatable to elevatea selected group of the needles immediately following the point of said insertion and to maintain said -needles in the elevated position as they leave said sta- .tion, means for retaining the insertedvyarn end against the latches of the needles of said group including means exterior of said cylinder engaging the intercepted yarn end and positioning the same above the latch-clearing position as the needles move toward the second of said stations, the cam means at said first station being operative to actuate the needles immediately following said group to pick up said yarn and to cast their loops, and cam means intermediate said stations for elevating the needles other than those of said group to latch clearing position prior to moving into the said second station, the cam means and yarn feed at said second station being actuatable to cause all the needles to take yarn and to cast their respective loops.

8. A circular knitting machine according to claim 7 wherein said yarn-retaining means includes means intermediate the needles and the cylinder axis for intercepting the inserted yarn to draw the yarn tautly across the needles of the elevated group and means for severing the intercepted yarn.

9. A circular knitting machine according to claim 8 wherein said yarn-retaining means includes separate means operative after severance of said yarn for retaining the yarn end against the latches of the selected group of needles as the latter move into the second station.

v10. A circular knitting machine according to claim 9 wherein the said separate means includes a needle within said group, means for adjusting the needle at the first station to a depressed position wherein the upper end thereof lies below the yarn end, and means for elevating the needle with the other needles extraneous to said group during their movement toward the second station and prior to the severing of said intercepted yarn whereby the needle passes behind the yarn end lying across the latches of the needles of said group to thereby clamp the yarn against the latches.

11. In a circular knitting machine comprising a rotary needle cylinder, latch needles in said cylinder, a pair of yarn feed stations relatively spaced circumferentially of the cylinder, and yarn feed means at each station including devices operated in timed relation with said cylinder for inserting and withdrawing yarn, said devices being actuatable to insert and withdraw yarn at predetermined points on the cylinder, means at one of said stations for elevating a selected group of needles immediately preceding said points and for retaining them in elevated positions as they leave the station so that said yarn lies across the outer faces of the needles of said group, yarn-engaging means exterior of said cylinder cooperative with the needles to support the yarn above the lower ends of the latches of the said group of needles, means for elevating the needles exclusive of those of the said group to latchclearing position prior to movement of the needles into the second station, and means at said second station to actuate the needles to take yarn from the feed means and to cast their loops.

12. A circular knitting machine according to claim 11 including means for severing the yarn end extending across the needles of the selected group prior to movement of said needles into the said second station and at a point between the needles and the axis of the cylinder.

13. A circular knitting machine according to claim 12 including means located between the needles and the cylinder axis for intercepting the inserted yarn to draw the yarn tautly across the said needles.

14. A circular knitting machine according to claim 13 v including yarn clamping means to receive and retain the yarn ends formed by operation of said severing means, References Cited in the file of this patent said clamping means being located between the said inter- UNITED STATES PATENTS cepting means and the severing means.

15'. A circular knitting machine according to claim 14 et g z" g including means operatively connected with the severing 2827780 i i; 5 1958 means for varying the clamping pressure of said clamp- 2872796 Peel '1959 ing means, and lost motion means affording freedom for n certain operations of the said pressure varying means in- FOREIGN PATENTS dependently of the severing means. 107,712 Australia June 14, 1939 

